Background: The female condom remains the only female-controlled method for preventing pregnancy and HIV/STIs. Little is known about its use among female sex workers (FSWs), a population at high risk of HIV/STIs and violence in the context of negotiation of male condoms. We examined the prevalence and correlates of female condom use among female sex workers who inject drugs (FSW-IDUs) in northern Mexico.Methods: FSW-IDUs ≥18 years old who reported injecting drugs and recent unprotected sex with clients participated in an ongoing behavioral intervention in Tijuana and Ciudad Juarez, Mexico. At baseline, participants underwent surveys and biological testing for HIV/STIs. Logistic regression was used to identify correlates of ever using female condoms.Results: To date, among 514 FSW-IDUs, 44 (8.6%) reported ever using female condoms, of whom 43.2% used them at least sometimes with regular partners, 45.5% with regular clients and 54.5% with non-regular clients. Six (13.6%) used the same female condom more than once; of whom, 5 did so ≥3 times in the past month. One FSW-IDU used two female condoms at the same time on four different occasions. Factors independently associated with female condom use were ever having an HIV test (AdjOR: 3.51; 95% CI:1.63-7.57) and having a regular client who was often/always angry when proposing male condom use in the past month (AdjOR: 3.83; 95% CI:1.70-8.62). Conclusions: Female condom use is low in this population of FSW-IDUs, possibly due to its cost, availability and/or acceptability. Since re-use of condoms may be a risk factor for HIV/STIs, it is imperative to identify barriers and promote education about their correct use. Additionally, female condom use may be a reflection of FSWs concern regarding potential violence from clients during condom negotiation, suggesting that client-based interventions are needed.